UFC welterweight champion Kamaru Usman underwent surgery to treat a double hernia on Tuesday in Philadelphia, according to a report by MMA Junkie.

Usman's manager, Ali Abdelaziz, told the website about the hernia surgery -- Usman would later reveal on Instagram that the surgery was performed on his midsection.

The 31-year-old Usman won the belt by defeating Tyron Woodley in a unanimous decision in UFC 235 on March 2. Before he'll make his first title defense, though, he'll need to get healthy.

"This is just for the best," Usman said on Instagram following the surgery. "I needed to get it fixed so I can be back and ready to defend that belt, man. I'm going to clean the division absolutely, so I got to make sure I'm no longer 30 percent. Got to make sure I get as close to 100 as I can, man."

It's unclear when Usman's first title defense will come. A day after Usman (15-1) won the title, UFC president Dana White said his first defense would come against Colby Covington (14-1).

Usman and Covington then got into a verbal confrontation while waiting in a line at The Palms casino in Las Vegas that weekend. On Wednesday morning, Usman did not mention Covington by name, but did hint at wanting to get back soon to take on a specific fighter.

Usman said Wednesday morning on Instagram he was already beginning the rehabilitation process and that he's "not letting that kid get away. I have to hand him a beating so let's make sure we're a little bit more than 30 percent and we'll go take care of that guy."